Throttle/Pedal Position Sensor/Switch E Circuit
The P2125 code means the vehicle's onboard diagnostic system has detected: Throttle/Pedal Position Sensor/Switch E Circuit. This is a critical severity code.
- Keep driving?
- No — stop driving
- DIY difficulty
- moderate
- Estimated cost
- $100 - $400 (parts and labor)
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Common Symptoms
- Reduced power mode or limp mode
- Accelerator pedal partially or fully unresponsive
- Engine stuck at idle
- Multiple throttle warning lights
- Check engine light on
Probable Causes (Ranked by Likelihood)
- Faulty accelerator pedal position sensor (track E) Very High
- Damaged wiring or connector for APP sensor E circuit High
- Open circuit in APP sensor E signal path Moderate
- Water intrusion in pedal connector Moderate
- PCM input circuit failure for E signal Low
Frequently Asked Questions
Can I drive with code P2125?
No. The PCM requires valid signals from both APP sensor tracks (D and E) to safely control the throttle. With the E circuit faulted, the vehicle enters limp mode and the pedal may be unresponsive.
What is the difference between APP sensor D and E circuits?
Most APP sensors have two independent signal tracks (D and E) for redundancy. The PCM compares both to verify the pedal position is accurate. Track E often outputs an inverse or offset voltage compared to track D. Both must agree for normal operation.
Can I drive on just one APP sensor track?
Some vehicles will allow limited operation on one track, but with severely reduced power. This is a temporary failsafe only. Both tracks must be functioning for normal driving. The backup track alone cannot provide the accuracy needed for safe throttle control.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
-
Monitor APP sensor E voltage with scan tool -- should change smoothly with pedal movement
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Compare APP sensor E to APP sensor D -- they should track proportionally (E is often inverse of D)
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Inspect APP sensor connector for moisture, corrosion, or physical damage
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Verify 5V reference and ground at the APP sensor connector
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Replace APP sensor/pedal assembly if signal is absent or erratic
Sources 1
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
P2125 on Diesel, EV & Equipment
The same code ID appears across other engines and platforms. The diagnostic flow varies by manufacturer — these are the platform-specific breakdowns:
Commonly Affected Vehicles
- 2007-2017 Toyota Camry
- 2008-2016 Nissan Altima
- 2009-2018 Honda Civic
- 2006-2015 Chevrolet Impala
- 2010-2019 Ford Fusion
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